Nebulizer with negative pressure structure

ABSTRACT

A nebulizer with a negative pressure structure includes a nebulization body, a carrying cavity, a nebulizing element and a negative pressure generating element. The carrying cavity is provided for carrying a nebulized liquid and has a through hole. The nebulizing element is installed at the through hole and includes a piezoelectric driving unit and a nebulizing plate disposed on a side of the piezoelectric driving unit. The negative pressure generating element is formed on the carrying cavity and provided for changing the volume of the carrying cavity or removing air from the carrying cavity to reduce the air pressure in the carrying cavity, so as to nebulize a liquid of low surface tension or high viscosity effectively.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. §119(a)on Patent Application No(s). 100221854 filed in Taiwan, R.O.C. on Nov.18, 2011, the entire contents of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to nebulizers, and moreparticularly to the nebulizer with a negative pressure structure.

2. Description of the Related Art

In general, a conventional nebulizer is comprised of a circularpiezoelectric plate, a nebulizing plate, a fixing plate and a cavity.For the nebulization of a liquid having a general surface tension, ifthe total air and liquid pressure value in the cavity is greater than orequal to the external air pressure value (approximately equal to one 1atmospheric pressure), the pressure at the inner side and the outer sideof the nebulizing plate reaches an equilibrium, and a nebulized liquidstored in the cavity can be attached onto an inner side of thenebulizing plate, so that the nebulized liquid will not spill out fromthe spray hole, so as to achieve the effects of preventing the sprayhole from being clogged easily and nebulizing the liquid effectively.

However, for a liquid having a low surface tension, the surface tensioncannot be maintained stably due to the too-low surface tension, so thatthe liquid will not spill from the inner side to the outer side of thespray hole of the nebulizing plate. If the nebulizing liquid has aspilling speed greater than the nebulization speed, the liquid willspill continuously from the spray hole of the nebulizing plate to coverthe surface of the nebulizing plate and result in clogging the sprayhole and failing to nebulize the liquid effectively.

If the air pressure in the cavity has a positive pressure value, and thenebulized liquid is attached onto the spray hole of the nebulizingplate, and the external air pressure is smaller than the air pressureand liquid pressure in the cavity, then the nebulized liquid in thecavity will spill out from the spray hole of the nebulizing plate toachieve a pressure equilibrium state. As to the liquid with a lowviscosity or a general viscosity, the small molecular weight andcoherence force between molecules can be separated during the process ofpassing droplets of the liquid through the spray hole of the nebulizingplate spray hole, so as to achieve an effective nebulization.

However, as to a liquid of a high viscosity, the liquid has a greatermolecular weight and Van der Waals' forces between molecules, theadherence force between molecules drives the liquid to spill out fromthe spray hole of the nebulizing plate, when the molecules of the liquidpass through the spray hole of the nebulizing plate for anebulization.As a result, the spray hole is covered by the liquid and fails tonebulize the liquid effectively. If a negative pressure state can bemaintained in the cavity, the nebulized liquid is attached onto thespray hole of the nebulizing plate, and the external air pressure isgreater than the pressure in the cavity, then the external air will movefrom the hole of the nebulizing plate into the cavity for a pressureequilibrium to reduce the spilling and facilitate the nebulized liquidand the external air to be exchanged by vibrations of the nebulizingplate and nebulize the liquid effectively.

SUMMARY OF THE INVENTION

To achieve the aforementioned objective, the present invention providesa nebulizer with a negative pressure structure comprising a nebulizationbody, a carrying cavity, a nebulizing element and a negative pressuregenerating element. The carrying cavity is provided for carrying anebulized liquid and has a through hole. The nebulizing element isinstalled at the through hole and includes a piezoelectric driving unitand a nebulizing plate disposed on a side of the piezoelectric drivingunit. The negative pressure generating element is formed on the carryingcavity and provided for changing the volume of the carrying cavity orremoving air from the carrying cavity to reduce the air pressure in thecarrying cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a nebulizer with a negative pressurestructure of a first preferred embodiment of the present invention;

FIG. 2 is a first schematic view of a nebulizer that produces a negativepressure effect in accordance with the first preferred embodiment of thepresent invention;

FIG. 3 is a second schematic view of a nebulizer that produces anegative pressure effect in accordance with the first preferredembodiment of the present invention;

FIG. 4 is a first schematic view of a nebulizer that produces a negativepressure effect in accordance with a second preferred embodiment of thepresent invention;

FIG. 5 is a second schematic view of a nebulizer that produces anegative pressure effect in accordance with the second preferredembodiment of the present invention;

FIG. 6 is a first schematic view of a nebulizer that produces a negativepressure effect in accordance with a third preferred embodiment of thepresent invention;

FIG. 7 is a second schematic view of a nebulizer that produces anegative pressure effect in accordance with the third preferredembodiment of the present invention;

FIG. 8 is a first schematic view of a nebulizer that produces a negativepressure effect in accordance with a fourth preferred embodiment of thepresent invention;

FIG. 9 is a second schematic view of a nebulizer that produces anegative pressure effect in accordance with the fourth preferredembodiment of the present invention;

FIG. 10 is a first schematic view of a nebulizer that produces anegative pressure effect in accordance with a fifth preferred embodimentof the present invention; and

FIG. 11 is a second schematic view of a nebulizer that produces anegative pressure effect in accordance with the fifth preferredembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The technical contents of the present invention will become apparentwith the detailed description of preferred embodiments and theillustration of related drawings as follows.

With reference to FIGS. 1 to 3 for an exploded view of a nebulizer andfirst and second schematic views of the nebulizer that produces anegative pressure in accordance with the first preferred embodiment ofthe present invention respectively, the nebulizer 1 comprises anebulization body 11, a carrying cavity 12, a nebulizing element 13, anegative pressure generating element 14, a slide element 15, a printedcircuit board 16, a battery holder 17 and a spray hole cover 18.

The nebulization body 11 is made of plastic or metal. In this preferredembodiment, the nebulization body 11 is substantially in a cylindricalshape and provided for containing the slide element 15, the printedcircuit board 16 and the battery holder 17. The printed circuit board 16is electrically coupled to the nebulizing element 13 and has a magneticswitch 161, and the battery holder 17 is provided for installing abattery to supply electric power required by the nebulizer 1. The sprayhole cover 18 is provided for covering a through hole 1211 of thecarrying cavity, and the through hole 1211 is provided for installingthe nebulizing element 13. In addition, the nebulization body 11 has aslide rail 111 disposed on an outer wall of the nebulization body 11 forinstalling the slide element 15 thereon. The slide element 15 has amagnet 151 used for changing the relative position of the magneticswitch 161 to turn on or off the nebulizer 1.

The carrying cavity 12 is disposed in the nebulization body 11 andextended upwardly, and the carrying cavity 12 is comprised of an innercup body 121 and an outer cup body 122, and the inner cup body 121 isprovided for carrying a nebulized liquid 9. The inner cup body 121 has acontaining space formed therein for carrying a nebulized liquid 9.

The nebulizing element 13 is comprised of a piezoelectric driving unit131, a nebulizing plate 132 and a structure plate (not shown in thefigure). The piezoelectric driving unit 131 can be a piezoelectricdriving unit of any type such as a piezoelectric ceramic device, and thestructure plate can be used for driving the piezoelectric driving unit131 to stably oscillate the nebulizing plate 132 and facilitate thenebulization process, and the nebulizing plate 132 is clamped betweenthe piezoelectric driving unit 131 and the structure plate.

The slide element 15 is provided for sliding to an ON position or an OFFposition on the nebulization body 11 to turn on or off the nebulizer 1respectively.

The negative pressure generating element 14 is comprised of an inner cupbody 121 and an outer cup body 122. The outer cup body 122 is comprisedof a spring 141, a one-way exhaust valve 142, an air-hole plate 143 anda pressing portion 144. The pressing portion 144 is disposed at aposition of an upper section of the outer cup body 122, and the one-wayexhaust valve 142 is installed in the pressing portion 144, and theair-hole plate 143 is installed at a position of a middle section in theouter cup body 122. The spring 141 is installed in the outer cup body122 of the carrying cavity 12, wherein an end of the spring 141 abutsthe pressing portion 144, and the other end of the spring 141 abuts theair-hole plate 143. The external peripheries of the pressing portion144, the one-way exhaust valve 142 and the one-way exhaust valve 142have a O-ring (not shown in the figure) separately, and a sealed spaceis formed by a contact portion between the inner cup body 121 and theouter cup body 122, and another sealed space is formed by a contactportion between the outer cup body 122 and the pressing portion 144.

In addition, the one-way exhaust valve 142 can be added and installed onthe air-hole plate 143, such that a user can press the pressing portion144 to decrease the volume occupied by the spring 141 and push the airoccupied in the volume of the spring 141 out from the one-way exhaustvalve 142 of the pressing portion. The pressing portion 144 resumes itsinitial position by the spring 141, so that the pressure in the volumeoccupied by the spring 141 is reduced to drive and open the one-wayexhaust valve 142 of the air-hole plate 143 and discharge the air fromthe inner cup body 121 to the volume occupied by the spring 141. Whenthe pressing portion 144 is pressed continuously, the air is dischargedfrom the inner cup body 121 to produce a negative pressure state of theair, so that the one-way exhaust valve 142 can be added and installedonto the air-hole plate 143 to prevent the pressing portion 144 frombeing pressed repeatedly that may cause an incomplete seal between theouter cup body 122 and the pressing portion 144 and also prevent theincomplete seal that may keep the external pressure in the inner cupbody 121 in equilibrium and maintain the in the negative pressure statein the inner cup body 121.

Wherein, the outer cup body 122 has a tenon 1221 formed at the top ofthe outer cup body 122 and provided for latching the inner cup body 121,so that the pressing portion 144 will not fall out from the outer cupbody 122 due to the upwardly exerted resilience force of the spring 141.

In addition, an embedding slot 1222 is formed on an inner side of theouter cup body 122, and a protrusion is formed on an outer side of theinner cup body 121, and the outer cup body 122 is sheathed on the innercup body 121, and the protrusion is latched to an end of the embeddingslot, so that the outer cup body 122 is fixed on the inner cup body 121.When a user presses the pressing portion 144, the spring 141 iscompressed and deformed, and the pressing portion 144 is moved in adirection towards the inner cup body 121. Now, the volume of thecarrying cavity 12 is increased and the air in the carrying cavity 12 iscompressed to increase the pressure in the carrying cavity 12 anddischarged from the one-way exhaust valve 142

When the use releases the pressing portion 144, the spring resumes itsoriginal position to drive the pressing portion 144 to move in adirection away from the outer cup body 122 and return the pressingportion 144 to its original position. Now, the volume of the carryingcavity 12 is equal to the volume before the inner cup body 121 ispressed, but some air has been discharged from the one-way exhaust valve142 and decreased. In addition, air is allow to enter but not to exit,due to the characteristic of the one-way exhaust valve 142, so that thevalue of the pressure in the carrying cavity 12 is smaller than theatmospheric pressure and in a negative pressure state.

Since the carrying cavity 12 is situated in a negative pressure state,therefore when the nebulized liquid in the carrying cavity 12 is anebulized liquid (with a viscosity of approximately 1.5˜20 cp which isgreater than that of water) with a low surface tension (such as 55dyne/cm), the air-liquid exchange produces droplets by vibrations basedon the principle of nebulization, and the nebulized liquid and externalair can achieve the exchange more effectively by the nebulizing plate inthe negative pressure state, so as to provide a more effectivenebulization.

With reference to FIGS. 4 and 5 for the second preferred embodiment ofthe present invention, the difference between this preferred embodimentand the previous preferred embodiment resides on the structure of thecarrying cavity 22 and the negative pressure generating element 24 only,and the structure and functions of other elements are the same as thoseof the first preferred embodiment and thus will not be repeated. InFIGS. 4 and 5, the negative pressure generating element 24 is an elasticplug covered onto a side of the carrying cavity 22 and the elastic plughas a one-way exhaust valve 241 and a latch portion 242, and a tenon 221is formed at an end of the carrying cavity 22 and corresponding to thelatch portion 242, and the one-way exhaust valve 241 is formed at an endof the elastic plug.

When the elastic plug is plugged into the carrying cavity 22, both sidesof the elastic plug are compressed and the elastic plug is deformed toretract the latch portion 242 and plug the elastic plug into an innerside of the tenon 221. Now, the air originally situated in the carryingcavity 22 is pushed out from the one-way exhaust valve 241 by elasticplug. When the elastic plug is released, the elastic plug is no longercompressed and it returns to its original form. Now, the latch portion242 is latched to an inner side of the tenon 221 to close the carryingcavity 22 and avoid air leakage. Some air is discharged from the one-wayexhaust valve 241 while plugging the elastic plug, and the volume of thecarrying cavity 22 substantially remains the same before and after theelastic plug is plugged, so that the pressure in the carrying cavity 22is smaller than the atmospheric pressure and becomes a negative pressurestate which facilitate the nebulized liquid and external air to have anexchange by the nebulizing plate for an effective nebulization.

With reference to FIGS. 6 and 7 for the third preferred embodiment ofthe present invention, the difference between this preferred embodimentand the previous preferred embodiments resides on the structure of thecarrying cavity 32 and the negative pressure generating element 34 only,and the structure and functions of other elements are the same as thoseof the previous preferred embodiments and thus will not be repeated.

In FIGS. 6 and 7, the carrying cavity is comprised of an inner cup body321 and an outer cup body 322, and the negative pressure generatingelement 34 is comprised of an embedding slot 341, a protrusion 342 and aone-way exhaust valve 343, and the embedding slot 341 is a curve grooveformed on the inner cup body 321, and the protrusion 342 is disposed onan inner side of the outer cup body 322 and latched into the embeddingslot 341, and the outer cup body 322 is fixed onto the inner cup body321. However, the present invention is not limited to the arrangement ofthis preferred embodiment only, but the embedding slot 341 can also beformed on an outer side of the inner cup body 321 or an inner side ofthe outer cup body 322, and the protrusion 342 can be disposed on aninner side of the outer cup body 322 or an outer side of the inner cupbody 321 and opposite to the embedding slot 341, and the protrusion 342is latched into the corresponding embedding slot 341. The one-wayexhaust valve 343 is installed at the top of the outer cup body 322.

When the outer cup body 322 is pulled in a direction away from the innercup body 321, the protrusion 342 is moved along the groove of theembedding slot 341 and latched to the bottom of the embedding slot 341.Now, the volume of the carrying cavity 32 is increased, and the one-wayexhaust valve 343 has the features of allowing air to exit only but notenter, so that the number of air molecules in the carrying cavity 32remains unchanged, and the carrying cavity 32 produces a negativepressure state to facilitate an exchange of the nebulized liquid andexternal air for a nebulization.

With reference to FIGS. 8 and 9 for the fourth preferred embodiment ofthe present invention, the difference between this preferred embodimentand the previous preferred embodiments resides on the structure of thecarrying cavity 42 and the negative pressure generating element 44 only,and the structure and functions of other elements are the same as thoseof the previous preferred embodiments and thus will not be repeated.

In FIGS. 8 and 9, the carrying cavity 42 is comprised of an inner cupbody 421 and an outer cup body 422, and the negative pressure generatingelement 44 is comprised of a telescopic body 441, a one-way exhaustvalve 442, a latch groove 443 and a protrusion 444, and the telescopicbody 441 and the one-way exhaust valve 442 are disposed at the top ofthe outer cup body 422, and the protrusion 444 is disposed on an innerside of the inner cup body 421 or an outer side of the outer cup body422, and the latch groove 443 is formed on an inner side of the outercup body 422 or an outer side of the inner cup body 421 and opposite tothe protrusion 444, and the protrusion 444 is latched into the latchgroove 443. Wherein, the telescopic body 441 is made of plastic and hasan elastic property when it is pulled and pushed.

When the telescopic body 441 is pulled in a direction away from theinner cup body 421, the telescopic body 441 is propped open and expandedoutwardly, so that the volume of carrying cavity 42 becomes bigger.Since the one-way exhaust valve 442 only allows the air to exit but notenter, therefore the number of molecules of the air in the carryingcavity 42 remains unchanged, and the pressure of the air in the carryingcavity 42 is smaller than the atmospheric pressure, so as to produce anegative pressure state and facilitate an exchange of the nebulizedliquid and outside air by the nebulizing plate for a nebulization.

With reference to FIGS. 10 and 11 for the fifth preferred embodiment ofthe present invention, the difference between this preferred embodimentand the previous preferred embodiments resides on the structure of thecarrying cavity 52 and the negative pressure generating element 54 only,and the structure and functions of other elements are the same as thoseof the previous preferred embodiments and thus will not be repeated.

In FIGS. 10 and 11, the carrying cavity 52 is disposed in thenebulization body and extended upwardly, and the carrying cavity 52 iscomprised of an inner cup body 521 and an outer cup body 522, and theinner cup body 521 is provided for carrying a nebulized liquid 9. Theinner cup body 521 has a containing space formed therein for carryingthe nebulized liquid 9. The outer cup body 522 is fixed on an outer wallof the inner cup body 521, and the negative pressure generating element54 is comprised of a piston rod 541, a one-way exhaust valve 542, atenon 543 and a latch portion 544, and the piston rod 541 is installedat the top of the outer cup body 525 and slidably disposed on an innerwall of the outer cup body 522, and the one-way exhaust valve 542 isinstalled on a side of the piston rod 541, and the tenon 543 is disposedon a side of the outer cup body 522, and the latch portion 544 is formedon a side of the piston rod 541 and corresponding to the tenon 543 ofthe outer cup body 522 to latch the piston rod 541 to the outer cup body522.

When the piston rod 541 is pressed, the volume of the carrying cavity 52is decreased, and the piston rod 541 is moved downwardly to the top ofthe inner cup body 521, so that some air is discharged from the one-wayexhaust valve 241. When the piston rod 541 is pulled upwardly to thetenon 543, the volume of the carrying cavity 52 is increased. Since theone-way exhaust valve 542 can prevent external air from entering intothe carrying cavity 52, therefore the pressure of air in the carryingcavity 52 is smaller than the atmospheric pressure to produce a negativepressure state to facilitate an exchange of the nebulized liquid andexternal air by the nebulizing plate for a nebulization.

In summation of the description above, the nebulizer with a negativepressure structure installed in the nebulizer in accordance with thepresent invention can be used for expanding the volume of the carryingcavity or removing air from the carrying cavity to reduce the airpressure of the carrying cavity, so that the carrying cavity is situatedin a negative pressure state to improve the effect of nebulizing aliquid of a low surface tension or a high viscosity.

What is claimed is:
 1. A nebulizer with a negative pressure structure,comprising: a nebulization body; a carrying cavity, formed in thenebulization body, for carrying a nebulized liquid, and having a throughhole and a one-way exhaust valve, which only allows air to exit but notenter the carrying cavity; a nebulizing element, installed at thethrough hole, and comprising: a structure plate having an inlet side andan outlet side; a piezoelectric driving unit, installed on the outletside of the structure plate; a nebulizing plate, installed on a side ofthe piezoelectric driving unit, the nebulizing plate being clampedbetween the piezoelectric driving unit and the structure plate, whereinthe carrying cavity is installed on the inlet side of the structureplate; and a negative pressure generating element, formed right adjacentto the carrying cavity, for changing the volume of the carrying cavity,wherein when the volume of the carrying cavity decreases, the one-wayexhaust valve allows air to exit but not enter the carrying cavity, andafter the volume of the carrying cavity restored a negative air pressurein the carrying cavity is created, so that a pressure in the carryingcavity is smaller than atmospheric pressure, and an external air willmove to a hole of the nebulizing plate, wherein the carrying cavitycomprises an inner cup body and an outer cup body, and the negativepressure generating element comprises a pressing portion, the one-wayexhaust valve and the pressing portion are disposed at positions of anupper section in the outer cup body, wherein when a user physically andmechanically presses the pressing portion, the pressing portion is movedin a direction towards the inner cup body to decrease a volume occupiedby the negative pressure structure and push air in the volume of thenegative pressure structure out from the one-way exhaust valve toproduces a negative pressure state in the carrying cavity.